SERUM ANTIBODY SYNTHESIS IN LARVAE OF THE BULLFROG, RANA CATESBEIANA

Abstract
1. Larvae of the American bullfrog, Rana catesbeiana, were thymectomized and sham-thymectomized at stages 25-29, representing an age range of about 60-200 days. After immunization at 25° ± 0.5° C. with goldfish serum proteins as antigens, specific precipitating antibodies were found in the majority of the sham-operated controls. In contrast, nearly all of the thymectomized group showed a markedly weakened response to goldfish serum antigens. 2. Lines of isoprecipitation were obtained in Ouchterlony tests with serums from some larvae immunized with isoantigens (whole adult serum). A longer period of immunization is apparently required to produce precipitins to serum isoantigens than to comparable xenogeneic antigens. To our knowledge, this is the first finding of serum isoantigens or allotypes and induced isoprecipitins in any poikilothermic vertebrate.